Teen pot use linked to IQ declines

Tuesday

Aug 28, 2012 at 2:35 AM

FROM WIRE REPORTS

FROM WIRE REPORTS

Teens may lose IQ points later in life if they smoke marijuana before age 18, according to a study that comes on the heels of a survey showing that the drug's use has risen in this age group for four straight years.

The research, reported Monday in the Proceedings of the National Academy of Sciences, found an average decline of eight points on IQ, or intelligence quotient, tests done at ages 13 and 38 among those who began using marijuana as a teenager. That compared with no decrease in those who used pot later in life.

Because marijuana is the most frequently used illegal drug in the U.S., looking at how it changes the brain is important, said study author Madeline Meier, a researcher at Duke University in Durham, N.C., who led the study.

Daily use among high school seniors is at a 30-year peak, said the National Institute on Drug Abuse. Twenty-three percent of high school students said they'd recently smoked pot.